A basic requirement for an absorbent article such as a sanitary napkin or the like is that the article must be shaped in such a manner that it can collect and absorb all discharged bodily fluid.
Since, for example, sanitary napkins are intended to be accommodated within a pair of normal panties, they are relatively small and, above all, often rather narrow. There is therefore an obvious risk that, by misplacing such an article within the panties or by it being deformed during use, it will not present a sufficiently large receiving surface for the discharged bodily fluid.
For example, it is not uncommon for the absorbent article to be placed too far forward or too far backwards or offset somewhat transversely. Another commonly occurring reason for bodily fluid to leak past an absorbent article and to soil the user's clothing is that the article is compressed between the legs of the user and thus becomes so narrow that the surface available for absorption becomes insufficient. Neither is it unusual for the side edges of the article to become folded over the surface of the article and thereby reduce the available surface.
An absorbent article of the type under consideration is generally maintained in the panties of the user by means of self-adhesive glue and/or a friction coating. When placing the article in the panties, it is difficult to obtain a placement which is optimal in relation to the body of the user. Normally, the crotch portion of the panties is used to determine where the article is to be placed. However, since panties are manufactured in a surprisingly large number of different models and sizes, the position and shape of the central portion provides an extremely unreliable indication of where in the panties an absorbent article should be positioned.
One way to reduce the risk of edge leakage due to deformation of the article during use is to provide the article with a preformed raised portion which, during use, is intended to contact the user's genitalia. In this manner, discharged bodily fluid can be intercepted as soon as it exits the user's body and be immediately absorbed within the article instead of running over its surface. In addition, a raised portion facilitates the placement of the absorbent article by the user in a correct position in relation to her body.
For this purpose, a raised portion of the type which is described in Swedish Patent Application No. 9604221-3 is particularly suitable. Such a raised portion has a predictable shape both before and during use and it maintains its shape irrespective of the movements of the user and the wetting to which the article is subjected. The raised portion is anatomically shaped, which implies that it is relatively narrow so as to be able to be inserted somewhat between the labia of the user during use without creating discomfort for the user.
Even though such a raised portion generally functions satisfactorily, it has been shown that, should the raised portion be subjected to large quantities of bodily fluid during a relatively short time, there is a risk that a quantity of the liquid will run over the side edges of the absorbent article. For example, such leakage can arise when the user of a sanitary napkin has been sitting or lying down for a long period and then suddenly gets up. Since the user has been sitting or lying down, a relatively large quantity of menstrual fluid collects in the user's vagina. As a result of a sudden change in body position, the entire quantity of collected fluid can be discharge in one go. A narrow raised portion of the type which is described in SE 9604221-3 does not therefore have a sufficiently large surface to be able to receive and absorb the entire quantity of liquid at once, which is why such sudden liquid flows often result in leakage.